Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With readOnlyHint=true already covering the safety profile, the description adds genuinely non-obvious behavior: the brief deliberately excludes verbatim competitor text, which shapes how the caller should use the result, and it explains scoping/precedence between the session-bound active Space and a per-call space_id override. It does not describe the size or structure of the returned brief beyond a field list.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tightly packed sentences, each doing distinct work: what the brief contains, how to use it, and how Space scoping resolves. Zero filler and the most decision-relevant content (original-copy constraint) is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description carries the burden of describing the return value and does so adequately by enumerating the brief's components. The nested body object is the main gap — an agent gets no hint about which identifiers are required or how they combine to select a brief. Space-override semantics are fully covered.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description does add real meaning for space_id by explaining the override-vs-session precedence and default source, which goes beyond the schema text. However, the four selector fields inside the required body (businessId, adId, competitorId, angleType) — the ones that determine which brief is produced and whether it is mandatory — get no mention at all.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a concrete deliverable — a structured brief containing angle type, the shape of a competitor's offer, and the hook pattern — rather than restating the name. It clearly frames the output as an input for drafting original copy, which separates it from data-returning siblings like get_angle_readout or get_competitor_offers. It stops short of naming any sibling explicitly, so an agent must infer the boundary.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear use context ('for writing ORIGINAL copy that argues a competitor's angle') and a hard constraint (never reuse competitor wording; write in the business's voice). It also documents the Space-selection behavior and names set_active_space as the alternative for changing scope. It does not state when to prefer it over get_creative_vocabulary or get_angle_gap, so the exclusion side is incomplete.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.